Oceanic ProPlus 4 - better explanation for the "complications" section?

[Cutaway]

Are there YouTube vids and website articles that explains better about the "complications" section of the Oceanic ProPlus 4? Its explanation is shallow and inadequate. For example, why did my deco alarm picked 10 ft. for stop deption vs. the 20 ft. shown in the manual? Is it SP6 or STG in the display? What is this TLA anyway? Since both Deep Stop and Safety Stop are disabled upon entering deco, does meeting the deco obligation negates the need for DS and SS?

Why is the manual lacking details? What is the SAT time showing with the Time To Fly? It often says 9 - blank blank. Do I explode and die if I dive again before it's 0? (trying to be onerous here...)

Thanks in advance.

 

[scubadada]

Hi @Cutaway

As you have not gotten a response, I will give it a try. I do not dive a ProPlus 4. My family has been diving ProPlus 2s since 2002 and we still have 3. My wife and daughter still dive them. I took a look at the ProPlus 4 user's manual. Your best bet would be to call or email Oceanic:

Our expert technicians are available by phone during our normal business hours of 8:00am – 5:00pm MDT, Monday – Friday (closed all major holidays) at (888) 270-8595
For Technical Support: TAC@huishoutdoors.com
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The deco example from p32 gives a stop depth of 20 ft, because that is the first required stop depth for that dive. After satisfying the obligation at 20 ft, there will be an obligation at 10 ft. Most short deco obligations start at 10 ft, not surprising that your computer gave that stop depth. I have done light deco of up to 14 min and have never had a stop depth on an Oceanic computer running DSAT of deeper than 10 feet. In the same example the last row displays SPG (submersible pressure gauge). It appears that a gas switch has been done in this example, to cylinder 2, and it must be monitored by SPG.

Correct, deep stop and safety stop are disabled when you enter decompression. There are no additional stops after you clear deco. I have always chosen to to pad my last deco stop by 3-5 minutes to further lower my surfacing tissue pressure. My backup computer to my Oceanic VT3 is now a Shearwater Teric. It displays SurfGF, eliminating any guesswork about surfacing from a dive close to NDL or in deco. I think it is safe to say that most authorities do not recommend deep stops in no stop diving. I have always left the deep stop option turned off. On the other hand, I always do at least a 3 min safety stop before surfacing from a no stop dive, even if my surfacing GF is already quite low. In addition, you might consider doing your final ascent slowly, as the tissue pressures jump considerably in that last 15 feet. I do my final ascent over at least a minute.

The FLY and SAT times are discussed on p17. The no fly time is arbitrarily set at 24 hours, longer that the general recommendation for repetitive no stop dives of 18 hours. The SAT time reflects tissue desaturation at sea level. It is displayed as 9-- any time it is greater than 9:59. They say that the desaturation time is usually shorter than the no fly time, this is generally true. However, I frequently have a desaturation time of greater than 24 hours when doing intense repetitive no stop dives with or without some light deco dives.

Good diving

 

[tursiops]

The FLY and SAT times are discussed on p17. The no fly time is arbitrarily set at 24 hours, longer that the general recommendation for repetitive no stop dives of 18 hours. The SAT time reflects tissue desaturation at sea level. It is displayed as 9-- any time it is greater than 9:59. They say that the desaturation time is usually shorter than the no fly time, this is generally true. However, I frequently have a desaturation time of greater than 24 hours when doing intense repetitive no stop dives with or without some light deco dives.

OP, just to expand on this: DAN USA says 18h, but DAN Europe says 24h, as do some other authorities. For deco dives -- which is what your example shows -- the typical recommendation is *at least* 24h. And as Scubadada's example shows, even repetitive non-deco dives may require more than 24h to "desaturate." Note that it is the *computer* that is desaturating, not your body, so beware of using computer desat times. 24h is a good rule to follow, but longer is always better, especially before flying.

 

[Cutaway]

Thank you @tursiops and @scubadada for responding! I do find it comical and surprised that the dive computer manual is written like it's from the 1980 Windows software manual. I can find more YouTube videos about drones, fishing, smartphones, GoPro, etc. explaining all features and then some.

I had a deco alarm dong the USNS Vandenberg wreck dive. I was already ascending when the alarm started at 73 ft. and 28 min. dive time (DECO time showed 3 min. at 10 ft). Seeing the alarm for the first time, I slowly ascend up the anchor line. But, I skipped the planned deep stop at 50 ft. for a deep stop because the DECO alarm kept asking me to go up to 10 ft. I then reached the 15 ft. safety stop which showed DECO time of 1 min. at 10 ft. So it seemed to me that the DECO obligation was reduced as I slowly ascended from 73 ft. to 17 ft. Where was this kind of details and examples in the manual?

So, I did 1 min. DECO obligation and 3 min. of SS manually, everything cleared. Surfaced with 530 PSI.

Again, thanks for your responses!

 

[tursiops]

Where was this kind of details and examples in the manual?

It is a manual about the computer, not about deco diving. You DO need to be more careful about going into deco without more training.

 

[scubadada]

Hi @Cutaway

Deco on the PP4 is described on pp 32-3, you posted one of the figures in your 1st post.

It appears that you were surprised when you went into deco on your ascent. By following your NDL, you would have known about the impending deco. You should not be going into deco by surprise and should spend more time planning your dive, including gas requirements.

I went back and looked at the PP4 manual, it is poorly written, even for Oceanic

 

[Cutaway]

You should not be going into deco by surprise and should spend more time planning your dive, including gas requirements.

I respect your advice. I did plan for the NDL dive. I studied the manual for PP4 and searched for its DECO feature in case of accidental entry since it was a 100-foot wreck dive. I was already ascending at a safe rate up the anchor line with minutes on the DTR and plenty of PSI. What I could not learn before the dive or anticipate was the computer's algorithm and how to interpret its behavior. I accept the lack of my knowledge of this computer and this experience. I also understand that it's all theoretical, and everyone's physiology is different. I also heard having two computers doesn't make it easier because of their difference. With proactive Google search, there is nothing adequate available. So, I did the remaining 1 min. DECO obligation and added my own three min. of SS manually. Everything cleared. I surfaced with 530 PSI. Learn your computer (and equipment) is acceptable. But I don't think expecting a better manual for a v4 product is not unreasonable. That was my ask of the original post. Where is this kind of info? If calling the hotline is how to get such information, then Oceanic is not a savvy business company. And PP4 is may be suitable for the PADI Open Water level use case.

Thanks again. I learned what I needed to learn from the responses. They were helpful.

 

[Centrals]

I went back and looked at the PP4 manual, it is poorly written, even for Oceanic

That is an compliment! Absolutely awful.

To the OP:
If the computer has gone to Deco mode. You better follow its instruction diligently ie. slow ascent to the indicated first required stop depth. Any delay will only increase the deco obligation. The only exception is out of gas!
Try not to let the ndl drops to less than 2 mins. Act early ie ascent to shallow depth earlier. Nothing to lose.